A soft urethane-foamed product is often used as a cushion member of a vehicle seat. The urethane-foamed product is acquired as a single molded product by disposing a reinforcing base fabric on a cavity surface of an urethane-foaming mold having a three-dimensional cavity, injecting an urethane-foaming crude liquid as a raw material into the mold, and foaming the urethane-foaming crude liquid under heating. The reinforcing base fabric is disposed on a rear surface opposite to a surface of the urethane-foamed product on which an occupant sits. The urethane-foamed product is attached to a seat frame such that the reinforcing base fabric comes in contact with a metal spring attached to the seat frame. The reinforcing base fabric has a function of preventing the urethane-foamed product from coming in direct contact with the metal spring and locally receiving a force to cause a crack or the like and preventing abrasion or noise due to friction or the like and enhances durability of the urethane-foamed product.
In the technique described in JP-A-2004-353153, a nonwoven fabric stacked body having a three-layered structure is employed as a reinforcing base fabric. A front surface layer as a top surface is impregnated with injected liquid urethane material and serves to be well bonded to a urethane-foamed product after the foaming. A rear surface layer as a bottom surface serves to provide a reinforcing effect based on fiber strength and to prevent noise from being generated due to friction with a metal spring. An intermediate layer serves to block the injected liquid urethane material so as not to permeate into the rear surface layer.
In the technique described in JP-A-2004-353153, when a fiber density per unit area of the nonwoven fabric of the intermediate layer is uneven, the injected liquid urethane material may permeate to the surface, which is a bottom surface of the rear surface layer, coming in contact with the metal spring and may cause generation of noise. When the thickness of the nonwoven fabric of the intermediate layer increases to prevent permeation of the urethane material, it is difficult to grow and thus followability of a mold shape in foaming urethane degrades. Accordingly, there is a possibility that breakage or formation of a crease will be caused.